1. Field of the Invention.
The present invention relates to the field of controlled flow, exhaust manifold systems and, more particularly, to apparatus for limiting the reverse flow of missile exhaust gases by closing off the cell of the fired missile from a common exhaust gas manifold or plenum tube connected thereto.
2. Description of the Related Art.
In certain military applications, particularly on warships having missile firing capability, the missiles are stored in a series of vertically oriented chambers or cells closely adjacent one another. Exhaust gas outlets are normally provided to duct rocket exhaust gases generated during intended or accidental rocket ignitions to a safe location. In such installations, manifolding of a number of chambers into a common exhaust duct or plenum tube has become conventional.
There have been a number of approaches to the problems attendant upon the use of a common exhaust duct with a plurality of missile storage chambers. It is important to be able to block the exhaust gases from a missile which is being fired from blowing out through the individual chambers of other missiles This is commonly accomplished by the use of doors or hinged panels which can open into the plenum chamber from the force of an impinging missile exhaust for the chamber containing the missile being fired and which can close off the passage at the base of a missile chamber opening into the exhaust plenum for other missiles. Eastman U.S. Pat. No. 2,445,423 discloses apparatus having a plurality of individual missile chambers coupled to a common plenum chamber with a plurality of hinged, spring-loaded doors at the juncture of each individual missile chamber with the plenum tube. These doors open for a rocket that is being fired and serve to confine the exhaust gases within the plenum chamber and away from other missile-storage chambers.
There is also the problem of a portion of the rocket exhaust backing up into the chamber of the missile being fired and possibly over-pressurizing that missile chamber.
My own prior U.S. Pat. No. 4,044,648, the entire disclosure of which is incorporated by reference as though fully set forth herein, discloses a pair of hinged doors at the base of each missile storage chamber in the passage connecting the chamber to an associated exhaust plenum duct. The pressure forces on opposite sides of the doors during the firing of a missile are balanced to control the degree to which the doors are opened in order to adjust the opening to the varying dimension of the rocket exhaust stream as the missile rises and leaves the chamber upon firing. As a consequence, the rocket exhaust stream functions as a suitable "gas plug" in the opening in order to prevent recirculation of the exhaust gases back into the chamber undergoing firing.
It is important to control the rocket exhaust gas stream so that the gas plug is effective to prevent recirculation of exhaust gases back into the chamber. Control of the rocket exhaust stream on a dynamic basis to develop the gas plug effect appears to be more effective for the intended purpose than the use of fixed structure such as baffles, valves, diverters or the like which oftentimes have the undesirable result of interfering with the direct exhaust gas stream in their attempt to control flow, limit reverse circulation, etc. My prior U.S. Pat. No. 4,683,798, the entire disclosure of which is incorporated by reference as though fully set forth herein, discloses hinged doors near the lower end of each missile storage chamber but spaced from the juncture with the common plenum chamber by a transition region which provides a smooth transition from a generally square cross-section chamber in which a missile is stored and launched to a round exit opening in the chamber which connects with the exhaust plenum. This enhances the gas plug effect and uses it to prevent recirculation of exhaust gases back into the chamber of the missile being fired.
My prior U.S. Pat. No. 4,686,884, the entire disclosure of which is incorporated by reference as though fully set forth herein, discloses an arrangement including sets of doors to close off missile storage chambers coupled to a common plenum chamber upon the firing of a missile in another chamber with the addition of pivotable deflector panels which are installed in transition sections between the missile storage and launch chambers proper and the common plenum chamber.
My prior U.S. Pat. No. 4,934,241, the entire disclosure of which is incorporated by reference as though fully set forth herein, discloses an arrangement, principally for shipboard use, wherein an uptake channel is provided to direct exhaust gases upward between a pair of adjacent missile cells. The arrangement includes a missile cell cover which is arranged to open for the missile being fired and to close automatically after the missile clears the storage chamber, thus preventing additional rocket exhaust from being channelled into the plenum at the base of the chamber. The cover is designed to open, when released from the latched closed position, to an open position in which it serves to divert uptake exhaust flow away from the missile as it exits the storage chamber. After the missile clears the canister and the rocket exhaust begins to impinge on the hatch cover, the hatch cover is unlocked from its open position by actuation of a drag flap that is deployed to help close the hatch cover.
My following listed prior patents deal with related aspects of rocket exhaust plenum chambers coupled to a plurality of missile launch canisters and the principles of using rocket exhaust gas flow to close the after doors of missile canisters not presently undergoing launch firing or maintaining such doors closed during the firing of a missile in another canister: U.S. Pat. Nos. 4,134,327, 4,173,919, 4,186,647, 4,324,167, and 4,373,420.